Scaffold-clamp



(No Model.)

T. N. SUBERS.

SGAFFOLD CLAMP.

atented Dec. 1, 1885.

O aw Unrrno STATES arnnrr Darren.

THOMAS N. SUBERS, OF PHILADELPHIA, PENNSYLVANIA.

SCAFFOLD-CLAMP.

SPECIFICATION forming part of Letters Patent No. 331,7:2, dated December1,1885.

Application filed May 18, 1885.

To ctZZ whom it may concern.-

Be it known that I, THOMAS N. SUBERs, a citizen of the United States,and a resident of Philadelphia, Pennsylvania, have invented certainImprovements in Scaffold-Clamps, of which the following is aspecification.

My invention consists of certain improvements in the scaffold-clamp forwhich I obtained Letters Patent No. 295,592, dated March 25, 1884, theobjects of my present improvements being to simplify the construction ofthe clamp, to render it more secure, and to make it available forsplicing sections of the vertical beams or posts of the scaffold.

In the accompanying drawings, Figure 1 is a perspective view showing theimproved clamp used for securing a longitudinal bar or stringer to avertical beam or post of the scaffold, and also showing a clampconstructed for use as a splice for said post or beam; Fig. 2,atransverse section of post and stringer, showing the bars of the clampin elevation, and also showing the means of tightening the clamp; Fig.3, a side view of Fig. 2, looking in the direction of the arrow; Fig. 4,a perspective view of the cam-lever shown in Figs. 2 and 8, and Fig. 5 aview showing a modified plan of carrying out one feature of myinvention.

A represents one of the upright posts or beams of a builders scaffold,and B one of the longitudinal bars or stringers of the scaffold for thesupport of the stretchers of the work in g-platforin. The stringer Bbears against the outer face of the post A, and on the outer side ofsaid stringer bears a bar, D, placed diagonally, so that its upper endprojects above the stringer B and beyond one side of the post A, thelower end projecting below the stringer B and beyond the opposite sideof the post. A similarly-arranged bar, D, bears against the inner faceof the post A, and the projecting ends of the two bars are connected bystraining-rods F. Each rod F passes through an opening near one end ofthe bar, D,and has a head bearing against the said bar, the opposite endof the rod passing through and projecting beyond the opposite bar D, andhaving a series of openings, a, to any one of which may be adapted apin, 72, whereby the bar D is retained in place against the outer sideof the stringer B. The bars D D have inwardly- Serial X0. 165,836. (NoInOllCl.l

projecting spurs or pins d, which are thrust into the post and stringer,and prevent the bars from slipping thereon, and in order to insure thefirm clamping of the post and stringer between the bars I draw thelatter forcibly together by means of the straining-rods and atightening-lever, G. This lever has a forked head, f, so that it canembrace the strainingrod, and in the back of this forked head of thelever are notches 13, adapted to a fulcrumpin, m,which can be insertedin any available opening of the rod F, so that the front portion, a, ofthe head of the lever,which is eccentric in respect to the fulcrum-pin,bears against the bar D,whereby when the lever Gis moved in thedirection of the arrow, Fig. 2, the bars D D are drawn forciblytogether, and the tight clamping of the post and stringer is insured,the bar D being retained in position, when fully tightened, by theinsertion of the pin Z) in the opening adjacent to the outer edge, ofthe bar.

In my former patent the straining-rods F ating-cranks. The objection tothis form of strainingrod is, that it can be loosened by mischievcus orevildisposed persons, and the security of the scaffold therebyendangered; moreover, the formation of a crank end or handle on eachstraining-rod materially in creases the expense of the same.

In the present case the lever G is detached from the straining-rod afterthe bars have been tightened and retained by the pin 6, so that but onelever is necessary, and there is no likelihood of the loosening of thebars, as in the former case.

Vhen the threaded straining-rod is usedinstead of the perforatedstraining-rods which I have described, I make the head of said rodsquare or of other polygonal form, and, preferably, tapered, as shown inFig. 5, the tightening-lever G in this case having a socket foradaptation to the said head of the strainingrod.

In constructing the device for use as a splice for sections of uprightposts or beams of the scaffold, upper and lower clamp-bars, D D or D D,are connected by a central web, J, as shown in Fig. 1, so as to form asingle structure, the lower bar of which clamps the lower section andthe upper bar the upper section were threaded, and had ends forming operof the upright. In this case there is a firm hold of the splicing-framesupon the posts by reason of the projecting studs which are formed uponthe frames, each clamp-bar being rigidly secured to the opposite bar ateach end by the strainingrods F.

I claim as my invention 1. Ascaffold-clamp comprisingtheopposite bars DD,having spurs d,the straining-rods F F, and a tightening-lever, G,detachable from said rods, all substantially as specified.

2. The combination of the opposite bars D D, the straining-rodsFF,having perforations a, the tightening-lever G, having a cam, n, andthe pins 12, whereby the bars are retained when tightened, as set forth.

3. The tightening-lever having a cam-head and notched in the rear of thehead for the reception of a fulcrunrpin, as specified.

4. The-tightening-leverhavingaforked end, 20 forming a cam,and notchedin the rear for receiving a fulcrum-pin, as specified.

5. The combination of sp1icing-frames,each comprising upper and lowerclamp-bars and a connecting-web, and each having retaining- 2 spurs withstraining rods F, whereby the frames are secured together at both endsof each clamp-bar, as set forth.

In testimony whereof I have signed my name to this specification in thepresence of two sub- 0 scribing witnesses.

THOMAS N. SUBERS.

Witnesses:

JOHN E. PARKER, HARRY SMITH.

